1. Field of the invention:
The present invention relates to a process for treating an acetylene polymer or a doped acetylene polymer by plasma-polymerization.
Acetylene polymers are a semi-conductor or an insulator having a specific resistance in the order of 10.sup.5 .OMEGA..cm to 10.sup.9 .OMEGA..cm [see Makromol. Chem., Vol. 175, p. 1565 (1978)]. It has been well-known that the electrical conductivity of an acetylene polymer can be increased remarkably by doping the acetylene polymer with iodine (I.sub.2), arsenic pentafluoride (AsF.sub.5) or the like [for instance, see J. Amer. Chem. Soc., Vol. 100, p. 1013 (1978)]. At present, attention is paid to said doped acetylene polymer as a new organic conductive material. However, an acetylene polymer or a doped acetylene polymer tends to react with oxygen, and when exposed in the air, said acetylene polymer or doped acetylene polymer is deteriorated by oxidation and the electrical resistance thereof increases greatly.
Deterioriation of the acetylene polymer or doped acetylene polymer by oxygen has been a great problem in the use of the acetylene polymer or doped acetylene polymer.
2. Description of the Prior Art:
Heretofore, a casting method, a chemical vapor deposition method (CVD method) and the like have been known as a coating method for the material protection. Among them, the casting method comprises coating a high molecular weight polymer solution on a solid surface, and then vaporizing the solvent to form a film of the high molecular weight polymer. This method has such defects that the adhesive strength between the film of a high molecular weight polymer and the substrate is weak, and so the film is apt to be peeled off. Another defect in this method is that the kind of the polymer is restricted because of the necessity of dissolving the high molecular weight polymer in a solvent.
Further, the CVD method is a method by which gasified reactants are subjected to chemical reaction in the gas phase or on the surface of a substrate, thereby depositing a new layer on the substrate surface. Like the casting method, this method has also the defects that the adhesive strength between the new layer and the substrate is weak, that the reaction proceeds spontaneously and hence the control of the reaction is difficult and the formation of a uniform layer is difficult and that the kind of reaction is restricted.